FanGraphs: Johan's slow decline

Old Johan Santana, he ain’t what he used to be, ain’t what he used to be. Oh sure, it’s tempting to look at his 2.96 ERA and 1.20 WHIP and say he’s still the same old dominant Santana, maybe with a tiny bit missing off of his fastball. But that’s just not the case.

At FanGraphs, we have a "dashboard" where you can select the stats you’d like to see for each player. Let’s recreate a dashboard for Santana here so his decline can come into stark focus. We’ll start in Minnesota in 2006, just because that was seemingly the beginning of the downward turn for him.

Johan's demise

A dwindling strikeout rate should concern the Mets and their fans.

The table sort of pulls it all together, doesn’t it? Since 2006, so many key indicators have gone the wrong way. The starkest of the group is Santana’s strikeout rate, which has gone from elite (9.66 K/9 would have been fifth among qualified starters last year) to below-average (so far this year, 7.01 K/9 is the league average). While his walk rate is still above-average (3.47 BB/9 is the league average this year), it’s certainly not the elite rate it once was.

Santana has never been a ground-ball guy, but now he's sporting the eighth-worst ground-ball rate in baseball among qualified starters. He used to get swinging strikes on that nasty changeup to offset the fly-ball part of his game, but even that is slipping recently. Also, his fastball velocity is degrading slowly and now doesn’t crack 90 mph on average.
The last stat, xFIP, is a number on the ERA scale that attempts to strip out batted-ball luck and corrects for home run rates. It’s an expected fielding-independent pitching number, in other words, and it sums up Santana’s entire slow decline in one place. It may be tough to believe, but Santana is, in many ways, an average starting pitcher right now.